Method and device to control a fuel split in a combustion device

Patent metadata

Field	Value
Publication number	US-11434825-B2
Application number	US-201515311934-A
Country	US
Kind code	B2
Filing date	May 27, 2015
Priority date	Jun 2, 2014
Publication date	Sep 6, 2022
Grant date	Sep 6, 2022

Abstract

A method, control unit and rotating machine for determining a fuel split setting value for adjusting a fuel split setting for a combustion device, the fuel split setting defining a relation between main fuel and pilot fuel. The method includes: retrieving a first information item correlated to heating value of supplied main fuel; retrieving a second information item correlated to combustor operating condition; retrieving at least one third information item representing stability of combustion; selecting a predefined pair of minimum and maximum boundary curves for the fuel split setting from a plurality of predefined pairs based on the first and second information items, the minimum and maximum boundary curves defining a band of fuel split settings permitted for a range of second information item values; determining the fuel split setting value within the selected pair of minimum and maximum boundary curves based on the third information item.

First claim

The invention claimed is:

1. A method for determining a fuel split setting value utilisable for adjusting a fuel split setting for a combustion device, the fuel split setting defining a relation between main fuel provided at primary fuel injection points and pilot fuel provided at at least one secondary fuel injection point, both being supplied to the combustion device for being combusted to a combusted fluid, the method comprising:
retrieving a first information item correlated to a heating value of the supplied main fuel;
retrieving a second information item correlated to a combustor operating condition when combusting the supplied main fuel and the pilot fuel;
retrieving at least one third information item, the at least one third information item representing stability of combustion in the combustion device;
selecting a predefined pair of minimum and maximum boundary curves for the fuel split setting from a plurality of predefined pairs of boundary curves based on the first information item and the second information item, wherein each predefined pair of minimum and maximum boundary curves of the plurality of predefined pairs of boundary curves defines a respective band of fuel split settings permitted for a range of second information item values, wherein each band is preset for a given Wobbe Index range of the supplied main fuel, wherein the Wobbe Index range defines a range of allowable heating values for the supplied main fuel; and
determining the fuel split setting value within the selected predefined pair of minimum and maximum boundary curves based on the at least one third information item, wherein the determined fuel split setting value being utilisable for adjusting the fuel split setting for the combustion device.

2. The method according to claim 1 , further comprising: setting a control parameter to control an amount of the main fuel provided to the primary fuel injection points and/or an amount of the pilot fuel provided to the at least one secondary fuel injection point based on the determined fuel split setting value.

3. The method according to claim 1 , further comprising: establishing a second interval of time,
establishing a first interval of time that is longer than the second interval of time, retrieving the first information item during the first interval of time,
retrieving the second information item during the second interval of time, and retrieving the third information item during the second interval of time.

4. The method according to claim 1 , wherein the first information item is retrieved in response to at least one of a change in composition for the supplied main fuel, a change in composition for the supplied pilot fuel, a switchover to a different source for the supplied main fuel, and a switchover to a different source for the supplied pilot fuel.

5. The method according to claim 1 ,
wherein the determining the fuel split setting value is executed continuously or in response to a change of the second information item and/or a change of the at least one third information item.

6. The method according to claim 1 ,
wherein, for the retrieving of the first information item, the heating value of the supplied main fuel is determined via a sensor signal.

7. The method according to claim 1 , wherein, for the retrieving of the second information item,
at least one of a firing temperature, an exit temperature of the combusted fluid exiting the combustion device, a thrust of the combusted fluid, and a turbine entry temperature of a turbine section of a rotating machine is determined or calculated via a sensor signal, or
an engine load of the rotating machine is determined via a load indicator by at least one of evaluating torque of a shaft and revolving speed of the shaft of the rotating machine driven in response of the combustion by the combustion device.

8. The method according to claim 1 , wherein, for the retrieving the at least one third information item, at least one sensor signal is evaluated, the at least one sensor signal representing at least one of combustion dynamics pressure, emission of NOx, emission of CO, a surface temperature of the combustion device, noise emission, vibration of the combustion device, a combustion gas temperature, and flame failure.

9. The method according to claim 1 ,
wherein said each predefined pair of minimum and maximum boundary curves is defined at least by a respective predefined maximum fuel split level provided over said range of second information item values and a respective predefined minimum fuel split level provided over said range of second information item values,
wherein the predefined maximum fuel split level represents a relation between the pilot fuel and the main fuel with a highest tolerable percentage of the pilot fuel in relation to the main fuel, and
wherein the predefined minimum fuel split level represents a relation between the pilot fuel and the main fuel with a lowest tolerable percentage of the pilot fuel in relation to the main fuel.

10. The method according to claim 1 , further comprising: selecting a predefined control logic method from a plurality of predefined control logic methods based on at least one of the first information item, the second information item, and the at least one third information item, wherein for the determining the fuel split setting value is performed by executing the selected control logic method.

11. The method according to claim 1 , wherein the main fuel and the pilot fuel both have the same chemical composition and/or both being a gaseous fuel.

12. The method according to claim 1 , wherein the second information item comprises at least one of a firing temperature, an exit temperature of the combusted fluid exiting the combustion device, thrust of the combusted fluid, and an engine load of a rotating machine downstream of the combustor device and driven in response of a flow of the combusted fluid.

13. The method according to claim 1 , wherein the at least one third information item comprises at least one of combustion dynamics pressure, emission of NOx, emission of CO, surface temperature of the combustion device, combustion dynamics noise emission, vibration of the combustion device, and flame instability.

14. A control unit for a combustion device, wherein the control unit comprises a processor configured for determining a fuel split setting value utilisable for adjusting a fuel split setting for the combustion device, the fuel split setting defining a split of a main fuel provided at primary fuel injection points and pilot fuel provided at at least one secondary fuel injection point, both supplyable to the combustion device for being combusted to a combusted fluid, wherein the control unit is configured to carry out a method comprising:
retrieving a first information item correlated to a heating value of supplied primary fuel of the main fuel;
retrieving a second information item correlated to a combustor operating condition when combusting the main fuel and the pilot fuel;
retrieving at least one third information item, the at least one third information item representing stability of combustion in the combustion device;
selecting a predefined pair of minimum and maximum boundary curves for the fuel split setting from a plurality of predefined pairs of boundary curves based on the first information item and the second information item, wherein each predefined pair of the minimum and maximum boundary curves of the plurality of predefined pairs of boundary curves defines a respective band of fuel split settings permitted for a range of second information item values, wherein each band is preset for a gi

Assignees

• Siemens Energy Global Gmbh & Co Kg

Inventors

• Alexander Varkey
• Liu Kexin
• Sanderson Victoria

Classifications

• F23R3/34

  Feeding into different combustion zones · CPC title

• F23N5/102

  using electronic means · CPC title

• F05D2260/964

  counteracting thermoacoustic noise · CPC title

• F23N5/022

  using electronic means (F23N5/04 - F23N5/14 take precedence) · CPC title

• F23R3/36

  Supply of different fuels · CPC title